FIELD OF THE INVENTION
The invention pertains to a drum-type washing machine with a multi-part fluid line extending between a drain opening located at the bottom of the tub and an opening located in the tub geodetically above the drain opening; the fluid line includes a line segment that serves solely to keep the washwater in the tub in circulation between the upper opening and the drain opening, and which has a solid pipe segment with a transparent region; a sensor is attached at the wall that responds to the turbidity in the washwater and includes an optical transmitter and an optical receiver.
One such drum-type washing machine is known from German patent disclosure DE 36 03 323 A1. There, the sensor is installed so far downward toward the bottom in the washwater drainage system that water remaining in the washwater drainage system can lead to calcification of the transparent region and reduce its transparency. This has a tendency to render the measurement values picked up by the sensor incorrect. Moreover, the prior art turbidity sensor is subject to severe shaking during spin cycles, since the line segment is secured by one end to the vibrating tub and on the other to the stationary washwater pump. The tub vibrations are therefore transmitted to the sensor. Moreover, the fastening points of the line segment are as a result subject to very severe stresses.